Insitu impedance heating for pipe wall repair

Abstract

The apparatus and method for insitu repair of pipes and conduits of varying diameter is taught by the specification and drawings. The invention utilizes impedance heating techniques and devices that previously been used to heat the contents within pipes and tanks. The invention can be adapted to utilize AC circuit components place either within the interior diameter of the pipe or adjacent to the outer pipe surface. The apparatus and method can include use of thermal couples or other components to monitor temperature and control electric current. The device and method can be variably used with electrical isolation components and techniques.

1 . A method for insitu repair of electrically conductive pipes comprising the following steps: 
 a. creating an electric current within a pipe wall;    b. using electrically resistive properties of the pipe wall to create heat within the pipe wall;    c. applying a thermally responsive material proximate to a surface of the pipe; and    d. utilizing the heat to cure or mold the thermally responsive material.    
   
   
       2 . The method of  claim 1  further comprising the step of creating an electrically conductive connection between the pipe wall and an electrical power source.  
   
   
       3 . The method of  claim 2  further comprising conducting DC current from the power source to the pipe wall.  
   
   
       4 . The method of  claim 2  further comprising conducting an AC current from the power source to the pipe wall.  
   
   
       5 . The method of  claim 4  further comprising utilizing a thermal setting material as the thermally responsive material.  
   
   
       6 . The method of  claim 5  wherein the thermal setting material is selected from a group consisting of phenolics, amino-formaldehydes, esters, epoxides, polyamides, and polyurethanes.  
   
   
       7 . The method of  claim 4  further comprising utilizing a thermal plastic material as the thermally responsive material.  
   
   
       8 . The method of  claim 7  wherein the thermal plastic material is selected from a group consisting of polyethylenes, polyolefin copolymers, polyvinyl chloride, polytetrafluoroethylene, polystyrenes, acrylic, polyamides, saturated polyesters, polycarbonate, polyacetal, polyphenylenes, and polysouphones.  
   
   
       9 . The method of  claim 2  wherein the thermally responsive material is placed on an inner surface of the pipe.  
   
   
       10 . The method of  claim 2  wherein the thermally responsive material is placed on the outer surface of the pipe.  
   
   
       11 . The method of  claim 9  further comprising the step of using an inflatable bladder with the placement of the thermally responsive material.  
   
   
       12 . The method of  claim 1  further comprising the step of using a tensioned pipe support with the placement of the thermally responsive material on the pipe wall surface.  
   
   
       13 . The method of  claim 10  further comprising the step of injecting a foaming liquid reactant proximate to the exterior of the pipe.  
   
   
       14 . The method of  claim 1  further comprising the steps of 
 a. Placing an electrically isolated AC circuit proximate to the pipe wall;    b. Powering the electric circuit; and    c. Inducing the electric current within the pipe wall.    
   
   
       15 . A method for insitu repair of electrically conductive pipes comprising the following steps: 
 a. Inducing an AC electric current within a pipe wall;    b. Using electrically resistive properties of the pipe wall to create heat within the pipe wall;    c. Applying a thermally responsive material proximate to a surface of the pipe; and    d. Utilizing the heat to cure the thermally responsive material.    
   
   
       16 . An apparatus for repairing pipes comprising: 
 a. a first electrical contact component removably attachable to a pipe wall;    b. a second electrical contact component removeably attachable to the pipe wall; and    c. an electrically conductive component in electric communication with at least one electrical contact component and connectable to an electric power source.    
   
   
       17 . An apparatus for repair pipes by inducing an electric current within a portion of an electrically conductive pipe wall to create heat that can mold or cure a thermally responsive repair material comprising an electric circuit component that can be placed proximate to a pipe wall surface and connectable to an AC power source.  
   
   
       18 . The apparatus of  claim 17  wherein the electric circuit component is attached to an inflatable bladder.  
   
   
       19 . The apparatus of  claim 17  wherein the electric circuit component is embedded with an inflatable bladder.  
   
   
       20 . The apparatus of  claim 17  wherein the electric circuit component is attached to a tensioned pipe support.